Question: $ { \left[\begin{array}{r}{2} \\ {4} \\ {-1}\end{array}\right]-\left[\begin{array}{r}{0} \\ {-2} \\ {1}\end{array}\right] = {?} } $
Answer: To find the difference of two matrices, subtract the corresponding items between each matrix. ${\left[\begin{array}{r}{2}-{0} \\ {4}-{-2} \\ {-1}-{1}\end{array}\right]}$ Now, simplify: ${\left[\begin{array}{r}{2} \\ {6} \\ {-2}\end{array}\right]}$